Question

This equation shows how a sapling's height depends on its age.

h = 2a+72
The variable a represents the age of the sapling in years, and the variable h represents the height of the sapling in inches.
How tall was the sapling when it was 5 years old.

Answer 1

Substitute the variable "a" with 5 to find the associated height

h=2(5)+72

Height of the sapling when it was 5 years old = 82 inches

Answer 2

82 inches

Explanation:

the equation that defines the height of a sampling in function of its age is:

`h=2a+72`

where
`h` is the height in inches, and
`a` is the age of the sapling.

Since we need to know the height of a sapling that is 5 years old, we have that:

`a=5`

so we substitute this value of
`a` into the equation for height:

`h=2(5)+72\\h=10+72\\h=82`

the height of the 5 years old sanpling is 82 inches